The invention relates to a broadcasting receiver for receiving broadcasting signals transmitted from a broadcasting station with multiple language audio signals and automatically selecting a certain broadcasting language to be outputted.
Conventionally, signal processing devices have been known that execute channel switching operations ahead of channel selection processes in order to shorten the time until audio and/or images are outputted when switched to specified channels and enhance user convenience (e.g., Japanese Unexamined Patent Publication No. 2000-152108). There is another type of broadcasting receiver that stores in a memory the type of language to be displayed on the display selected by the user, automatically extracts audio signals of the language when multiple broadcasting languages are received, and generates output from a speaker using the language (e.g., Japanese Unexamined Patent Publication No. 11-98434). Moreover, there are other broadcasting receivers for conventional analog broadcasts that can handle a single audio channel (mono) or two audio channels (stereo/sub audio program).
Furthermore, in recent years, broadcasting stations in North America are distributing digital broadcasts based on ATSC (Advanced Television Systems Committee) Standards. As a result, certain types of broadcasting receivers (set top box; hereinafter called “STB”) are becoming popular that receive these digital broadcasts and convert them into image signals that can be received by televisions designed for analog broadcasts based on the existing NTSC (National Television Systems Committee) Standards.
Those digital broadcasts are distributed, by each channel assigned with a different broadcast language, and such broadcast languages are sometimes distributed with audio signals of three or more kinds of languages. The combination of these languages used for these audio signals vary with the program compositions, thus causing stations to transmit audio signals of various languages depending on programs and time zones. Digital broadcasting can distribute audio signals of audio channels of up to 5.1 channels. The number of audio channels varies with the composition of a particular broadcasting program and each station distributes audio signals of a different number of audio channels for a given time zone.
It is possible to enhance user convenience by providing a STB for receiving such digital broadcasting with various functions of the signal-processing device disclosed by Japanese Unexamined Patent Publication No. 2000-152108 and of the broadcasting receiver disclosed by Japanese Unexamined Patent Publication No. 11-98434. However, the signal-processing device of the former is not capable of automatically selecting a broadcasting language specified by the user from the received broadcasting signals. Also, the broadcasting receiver of the latter is not capable of automatically selecting an optimum language by assigning an order of priority to multiple languages as only the language used for display is selected as the audio language. Moreover, neither of these devices is capable of always automatically determining the optimum number of audio channels within the maximum number of channels allowed for output to the speaker connected to the device in correspondence with audio channels that are constantly changing in accordance with varying program compositions. Consequently, the user must set the broadcasting language and the number of audio channels each time the channel is changed, so that this setup operation is cumbersome and the devices are not user-friendly.